Numerical analysis of rectangular microstrip patch over ground plane with rectangular aperture

Abstract

SUMMARYIn this paper, a rigorous full-wave analysis of rectangular microstrip patches over ground planes with rectangular apertures in substrates containing isotropic and anisotropic materials is presented. The dyadic Green's functions of the problem are e ciently determined in the vector Fourier transform domain. The integral equations for the unknown patch current and aperture ÿeld are solved numerically by applying the Galerkin method of moments. The TM set of modes issued from the magnetic wall cavity model are used to expand the unknown current on the patch. Also, the same basis functions are used for approximating the aperture ÿeld in accordance with the concept of complementary electromagnetic structures. The validity of the solution is tested by comparison of the computed results with experimental data. Numerical results show that changes in aperture length can drastically shift the resonant frequency. The aperture width, on the other hand, can be used for a ÿne adjustment of the operating frequency. Other results also indicate that dielectric anisotropy e ect is especially signiÿcant when the size of the aperture is similar to that of the patch.

Fourier Transform Domain Analysis of High T c Superconducting Rectangular Microstrip Patch over Ground Plane with Rectangular Aperture

“…Numerical results show that the resonant frequencies of the superconducting patches over ground planes without apertures are larger than those obtained with apertures. This result agrees with that discovered theoretically for perfectly conducting patches [8][9][10]. Other results also indicate that as the thickness of the superconducting film grows, the resonant frequency increases for antennas without apertures as well as for antennas with apertures.…”

“…The operating temperature is T= 50 K. It is noticed that the resonant frequencies of the superconducting patches over ground planes without apertures are larger than those obtained with apertures. This result agrees with that discovered theoretically for perfectly conducting patches [8][9][10].…”

“…As explained in [13] (see Eq. 6 and (38)), all these dyadic Green's functions can be obtained in a straightforward way in terms of their vector Fourier transform version, which, in turn, can be determined very efficiently using the explicit expressions shown in [9,. Equations 1 and 2 can be rewritten as follows:…”

“…To the best of our knowledge, this subject has not been reported in the open literature; the only published results on the full-wave analysis of microstrip antennas with apertures in the ground planes refer to perfectly conducting patches [7][8][9][10]. To include the effect of the superconductivity of the microstrip patch in the full-wave analysis, a complex surface impedance is considered.…”

“…Several advantages have been obtained by using this feeding configuration [7][8][9][10]. Such advantages include weak parasitic radiation in the useful direction with respect to conventionally fed antennas and optimal performance for both the feeding network and antenna element.…”